`struct` seems missing from the spec

[filmil]

The spec at https://github.com/bazelbuild/starlark/blob/master/spec.md seems not to mention struct.

OTOH, https://github.com/google/starlark-go/blob/master/starlarkstruct/struct.go exists.

[lgalfaso]

struct is not part of the spec. An implementation may define additional built-in functions, data types and many other things. The spec is clear about this right at the start.

A Starlark interpreter is typically embedded within a larger application, and this application may define additional domain-specific functions and data types beyond those provided by the core language.

Similar language is all over the spec.

[filmil]

You're technically correct. Which we all know is the best kind of correct. :)

[lgalfaso]

There are a few parts that the Starlark spec and Bazel do not agree (eg https://bazel.build/rules/lib/core states that json is a data type of the core language and points to this spec on "built-in constants and functions" that does not include json in the spec). That said, in the case of struct both agree, it is not part of the spec and Bazel does not claim that this is the case.